LIXTE Biotechnology Holdings, Inc. announced a Phase 1b collaborative clinical trial to assess whether adding Lixte's LB-100 to GSK's programmed death receptor-1 (PD-1)-blocking monoclonal antibody, dostarlimab, may enhance the effectiveness of immunotherapy in the treatment of ovarian clear cell carcinoma (OCCC). The clinical trial is sponsored by The University of Texas - MD Anderson Cancer Center and will be conducted at MD Anderson and will also be open at Northwestern University's Robert H. Lurie Comprehensive Cancer Center. LIXTE will provide LB-100; GSK will provide dostarlimab and financial support for the clinical trial.

The clinical trial is based on the observation of longer survival of patients with OCCC treated with immunotherapy whose cancer cells have an acquired gene mutation resulting in a reduction in PP2A. This finding was reported by the lead clinical investigators of this new trial1: Amir Jazaeri MD, Professor of Gynecologic Oncology at MD Anderson, and Emily Hinchcliff, MD, MPH, Assistant Professor of Obstetrics and Gynecology at Northwestern University Feinberg School of Medicine. The observation by Drs.

Jazaeri and Hinchcliff, that a genetically acquired reduction in PP2A enhances sensitivity to immunotherapy, raises the possibility that reducing PP2A pharmacologically with LB-100 will enhance the anti-tumor effect of the PD-1 blocking monoclonal antibody dostarlimab in patients with OCCC lacking the genetic reduction in PP2A.